In these critical areas, actions for intervention and rescue on the part of firefighters or law enforcement personnel in case of an accident are particularly risky for the injured people, for their rescuers and for all the people involved in the accident, since the escape routes are often difficult to detect. The smoke of a fire, darkness or fog are the factors that most significantly compromise the effectiveness and swiftness of an intervention.
These factors can themselves be the cause of an accident or can worsen one, since even in the absence of an accident, in certain critical areas (such as for example tunnels) it is necessary to ensure safety by preventing accidents caused by particular environmental conditions.
Systems are currently known which send images from fixed stations to a control center, which coordinates operations by radio.
Portable or helmet-mounted mobile systems that improve the vision of the individual user are also known. In particular, U.S. Pat. No. 6,255,650 in the name of Flir Systems, Inc. describes a system that is formed by an infrared (IR) television camera, a display, electronic and power supply circuits which are integrated in a portable, stand-alone apparatus that is shaped so as to be worn on one's head; this television camera-display system improves vision in environments with dense particulate, with extreme temperatures such as those that occur in fires. Vision can be monoscopic or stereoscopic and is enhanced by color-coding the temperature, by means of a processor and by way of reflective and opaque lenses arranged approximately at eye level in order to produce bright and sharp images.
Optionally, the system comprises an external video recorder and transmitter; the video transmitter also transmits radiometric data.
U.S. Pat. No. 5,200,827 describes another video camera-display system that is conceived to be mounted on the helmet of a soldier. The system allows to display at close range pictures that originate from a remote location and is used for example to transmit pictures from the combat area toward the rearguard.
Transmission between the video camera (mounted on a rifle or hinged on the helmet) and the display (mounted on the helmet) occurs by means of an electric wire, optical fiber or wirelessly, and a transmitter allows multiple individuals to view the picture that arrives from a single video camera; each one of the involved individuals can select the picture generated by several remote video cameras.
The display used in U.S. Pat. No. 5,200,827 is transparent in order to allow the user to view the environment; in particular, the picture is obtained by means of a holographic projection on a clear peak. Moreover, the display operates with an image separator arranged on the line of sight of the person in order to allow to view a superimposed scene of the object on the line of sight and on the display.
Finally, patent FR 2602347 describes an apparatus that is constituted by an infrared sensor, a laser rangefinder and a device for alignment with the rangefinder. The apparatus operates on two optical communication pathways that work in different spectral domains.
Known systems and devices are limited in monitoring and rescue applications in critical areas because they do not integrate information effectively. In particular, fixed-station systems require a control center that coordinates operations by radio, and this control center does not retransmit received pictures or any real-time processing of said pictures.
Furthermore, the pictures displayed on the display originate from a single video camera and interaction with other video cameras occurs according to a direct link.